Update on hereditary gastrointestinal cancers: Lynch syndrome and familial adenomatous polyposis syndromes
Hereditary causes, due to defects in certain genes, account for up to 10% of all colorectal cancers (CRCs). These high-risk hereditary predisposition syndromes have been associated with a significantly increased lifetime risk of cancer, with some approaching 100%. In addition, up to 20% of patients with CRC have common familial cancer, meaning there is a strong family history of CRC but no one genetic defect has been identified.